Effects of Organic Substrates on Earthworm Behavior : Do Worms Show a Preference?

Abstract

From the time of the last glaciation, earthworms were absent from northern soils, until non-native species were accidently imported from Europe in the 1600’s. Earthworms are “ecosystem engineers” that can modify soil structure, alter soil chemistry, and accelerate nutrient cycling. These activities increase the fertility of agricultural soils but can also bring irreversible changes to natural ecosystems. In each case earthworms play an important role, but while many studies have focused on earthworm impacts, fewer have investigated the factors that influence their movement. We conducted field and laboratory experiments to study how food influences earthworm aggregation and burrowing. The field experiment examined the effect of food quality on earthworm aggregation; the laboratory experiment examined how the presence or absence of food affected earthworm burrowing.